Electronic watch having antimagnetic characteristic

Claim 1

In an electronic watch of the type having a watch movement including a base plate having a pair of opposed major surfaces, an electromechanical transducer mounted on a first of said major surfaces and including a rotor operable to rotate by energization of said transducer, means defining a bridge structure a distance above said first major surface wherein a portion of said bridge structure comprises mounting means mounting said rotor for rotation, the improvement which comprises: shielding means defining magnetic shields above and below said transducer for shielding the same from magnetic fields external to the watch; said shielding means comprising a first plate-like portion of antimagnetic material carried by said bridge structure at substantially the same distance from said base plate as said bridge structure and overlying a portion of said electro-mechanical transducer, and a second plate-like portion of antimagnetic material disposed at the second major surface of said base plate and underlying a portion of said transducer, said second major surface having a sufficiently deep recess therein for receiving said second plate-like portion of said shielding means so that said second plate-like portion does not extend above said second major surface, said first and said second plate-like portions respectively overlying and underlying said electro-mechanical transducer sufficiently to effectively shield said transducer from magnetic fields external to the watch, and said first and second plate-like portions being spaced a distance not exceeding a distance between said bridge structure and said second major surface whereby said shielding means does not contribute to a thickness of the watch movement.